rust_pixel 2.4.0

// RustPixel
// copyright zipxing@hotmail.com 2022～2026

//! This module provides a unified Input Event, describing events from keyboard and mouse
//! Input events triggered by renders adapter such as web, sdl or cross are converted here to
//! unified Event

use bitflags::bitflags;
use std::hash::{Hash, Hasher};

#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Hash)]
pub enum Event {
    /// A single key event with additional pressed modifiers.
    Key(KeyEvent),
    /// A single mouse event with additional pressed modifiers.
    Mouse(MouseEvent),
}

#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
pub struct MouseEvent {
    /// The kind of mouse event that was caused.
    pub kind: MouseEventKind,
    /// The column that the event occurred on (8 pixel width, shared by TUI and Sprite).
    pub column: u16,
    /// The row that the event occurred on (8 pixel height, Sprite coordinate system).
    /// For TUI layer, use `row / 2` to convert to 16 pixel height coordinates.
    pub row: u16,
    /// The key modifiers active when the event occurred.
    pub modifiers: KeyModifiers,
}

#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
pub enum MouseEventKind {
    /// Pressed mouse button. Contains the button that was pressed.
    Down(MouseButton),
    /// Released mouse button. Contains the button that was released.
    Up(MouseButton),
    /// Moved the mouse cursor while pressing the contained mouse button.
    Drag(MouseButton),
    /// Moved the mouse cursor while not pressing a mouse button.
    Moved,
}

#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
pub enum MouseButton {
    /// Left mouse button.
    Left,
    /// Right mouse button.
    Right,
    /// Middle mouse button.
    Middle,
}

bitflags! {
    /// Represents key modifiers (shift, control, alt, etc.).
    ///
    #[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
    pub struct KeyModifiers: u8 {
        const SHIFT = 0b0000_0001;
        const CONTROL = 0b0000_0010;
        const ALT = 0b0000_0100;
        const SUPER = 0b0000_1000;
        const HYPER = 0b0001_0000;
        const META = 0b0010_0000;
        const NONE = 0b0000_0000;
    }
}

#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
pub enum KeyEventKind {
    Press,
    Repeat,
    Release,
}

bitflags! {
    /// Represents extra state about the key event.
    #[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
    pub struct KeyEventState: u8 {
        /// The key event origins from the keypad.
        const KEYPAD = 0b0000_0001;
        /// Caps Lock was enabled for this key event.
        const CAPS_LOCK = 0b0000_1000;
        /// Num Lock was enabled for this key event.
        const NUM_LOCK = 0b0000_1000;
        const NONE = 0b0000_0000;
    }
}

/// Represents a key event.
#[derive(Debug, PartialOrd, Clone, Copy)]
pub struct KeyEvent {
    /// The key itself.
    pub code: KeyCode,
    /// Additional key modifiers.
    pub modifiers: KeyModifiers,
    /// Kind of event.
    pub kind: KeyEventKind,
    /// Keyboard state.
    pub state: KeyEventState,
}

impl KeyEvent {
    pub const fn new(code: KeyCode, modifiers: KeyModifiers) -> KeyEvent {
        KeyEvent {
            code,
            modifiers,
            kind: KeyEventKind::Press,
            state: KeyEventState::empty(),
        }
    }

    pub const fn new_with_kind(
        code: KeyCode,
        modifiers: KeyModifiers,
        kind: KeyEventKind,
    ) -> KeyEvent {
        KeyEvent {
            code,
            modifiers,
            kind,
            state: KeyEventState::empty(),
        }
    }

    pub const fn new_with_kind_and_state(
        code: KeyCode,
        modifiers: KeyModifiers,
        kind: KeyEventKind,
        state: KeyEventState,
    ) -> KeyEvent {
        KeyEvent {
            code,
            modifiers,
            kind,
            state,
        }
    }

    // modifies the KeyEvent,
    // so that KeyModifiers::SHIFT is present iff
    // an uppercase char is present.
    fn normalize_case(mut self) -> KeyEvent {
        let c = match self.code {
            KeyCode::Char(c) => c,
            _ => return self,
        };

        if c.is_ascii_uppercase() {
            self.modifiers.insert(KeyModifiers::SHIFT);
        } else if self.modifiers.contains(KeyModifiers::SHIFT) {
            self.code = KeyCode::Char(c.to_ascii_uppercase())
        }
        self
    }
}

impl From<KeyCode> for KeyEvent {
    fn from(code: KeyCode) -> Self {
        KeyEvent {
            code,
            modifiers: KeyModifiers::empty(),
            kind: KeyEventKind::Press,
            state: KeyEventState::empty(),
        }
    }
}

impl PartialEq for KeyEvent {
    fn eq(&self, other: &KeyEvent) -> bool {
        let KeyEvent {
            code: lhs_code,
            modifiers: lhs_modifiers,
            kind: lhs_kind,
            state: lhs_state,
        } = self.normalize_case();
        let KeyEvent {
            code: rhs_code,
            modifiers: rhs_modifiers,
            kind: rhs_kind,
            state: rhs_state,
        } = other.normalize_case();
        (lhs_code == rhs_code)
            && (lhs_modifiers == rhs_modifiers)
            && (lhs_kind == rhs_kind)
            && (lhs_state == rhs_state)
    }
}

impl Eq for KeyEvent {}

impl Hash for KeyEvent {
    fn hash<H: Hasher>(&self, hash_state: &mut H) {
        let KeyEvent {
            code,
            modifiers,
            kind,
            state,
        } = self.normalize_case();
        code.hash(hash_state);
        modifiers.hash(hash_state);
        kind.hash(hash_state);
        state.hash(hash_state);
    }
}

/// Represents a modifier key (as part of [`KeyCode::Modifier`]).
#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
pub enum ModifierKeyCode {
    /// Left Shift key.
    LeftShift,
    /// Left Control key.
    LeftControl,
    /// Left Alt key.
    LeftAlt,
    /// Left Super key.
    LeftSuper,
    /// Left Hyper key.
    LeftHyper,
    /// Left Meta key.
    LeftMeta,
    /// Right Shift key.
    RightShift,
    /// Right Control key.
    RightControl,
    /// Right Alt key.
    RightAlt,
    /// Right Super key.
    RightSuper,
    /// Right Hyper key.
    RightHyper,
    /// Right Meta key.
    RightMeta,
}

/// Represents a key.
#[derive(Debug, PartialOrd, PartialEq, Eq, Clone, Copy, Hash)]
pub enum KeyCode {
    /// Backspace key.
    Backspace,
    /// Enter key.
    Enter,
    /// Left arrow key.
    Left,
    /// Right arrow key.
    Right,
    /// Up arrow key.
    Up,
    /// Down arrow key.
    Down,
    /// Home key.
    Home,
    /// End key.
    End,
    /// Page up key.
    PageUp,
    /// Page down key.
    PageDown,
    /// Tab key.
    Tab,
    /// Shift + Tab key.
    BackTab,
    /// Delete key.
    Delete,
    /// Insert key.
    Insert,
    /// F key.
    /// `KeyCode::F(1)` represents F1 key, etc.
    F(u8),
    /// A character.
    /// `KeyCode::Char('c')` represents `c` character, etc.
    Char(char),
    /// Null.
    Null,
    /// Escape key.
    Esc,
    /// Caps Lock key.
    CapsLock,
    /// Scroll Lock key.
    ScrollLock,
    /// Num Lock key.
    NumLock,
    /// Print Screen key.
    PrintScreen,
    /// Pause key.
    Pause,
    /// Menu key.
    Menu,
    /// The "Begin" key (often mapped to the 5 key when Num Lock is turned on).
    KeypadBegin,
    /// A modifier key.
    Modifier(ModifierKeyCode),
}